Aspect Ratio Calculator
Calculate and convert aspect ratios for images, videos, and screens. Enter dimensions to find the ratio, resize while maintaining proportions, and view common resolution presets for HD, 4K, 8K, and more.
How to Use the Aspect Ratio Calculator
- Enter your width and height dimensions in the first section to calculate the aspect ratio
- Click any common ratio preset button (16:9, 4:3, 1:1, etc.) to quickly set standard dimensions
- Use the "Resize by Ratio" section to calculate new dimensions while maintaining the aspect ratio
- Enable "Lock aspect ratio" to automatically calculate height when you change width (or vice versa)
- Click any resolution in the common sizes grid to copy it to your clipboard
What is Aspect Ratio?
Aspect ratio is the proportional relationship between the width and height of an image, video, or screen. It is expressed as two numbers separated by a colon (e.g., 16:9), representing the width-to-height ratio. The first number always represents the width, while the second represents the height. This relationship remains constant regardless of the actual pixel dimensions, meaning a 1920x1080 image has the same 16:9 aspect ratio as a 3840x2160 image.
Understanding aspect ratios is essential for video production, photography, web design, and ensuring content displays correctly across different devices. When you resize an image while maintaining its aspect ratio, the proportions stay the same, preventing distortion. If you change dimensions without preserving the ratio, your content will appear stretched or squished, which is particularly noticeable with faces and circular objects.
Common Aspect Ratios and Their Uses
- 16:9 (Widescreen): The standard for HDTVs, computer monitors, YouTube videos, and most streaming content. Resolutions include 1280x720 (720p), 1920x1080 (1080p), and 3840x2160 (4K).
- 4:3 (Standard): Traditional TV and early computer monitors. Still used for some tablets and presentation slides. Common resolutions are 640x480, 800x600, and 1024x768.
- 1:1 (Square): Popular for social media platforms like Instagram posts, profile pictures, and album artwork. Creates balanced, symmetrical compositions.
- 21:9 (Ultrawide): Used for cinematic films and ultrawide gaming monitors. Provides an immersive viewing experience with more horizontal field of view.
- 9:16 (Vertical): The standard for smartphone vertical videos, Instagram Stories, TikTok, and YouTube Shorts. Essential for mobile-first content.
- 3:2: Common in photography, used by most DSLR and mirrorless cameras. Standard print sizes like 4x6 inches use this ratio.
- 4:5: Popular for Instagram portrait posts, providing more vertical space than square while fitting well in mobile feeds.
Aspect Ratio Formulas
Calculate Ratio: ratio = width / height
Simplified Ratio: Divide both width and height by their GCD (Greatest Common Divisor). For example, 1920/1080 = 16/9 because both divide evenly by 120.
Calculate Height from Width: height = width / (ratio_width / ratio_height)
Calculate Width from Height: width = height x (ratio_width / ratio_height)
Tips for Working with Aspect Ratios
- Always check the required aspect ratio before creating content for specific platforms to avoid cropping important elements
- When editing photos, use crop overlays to visualize how different ratios will frame your subject
- For video projects, decide on your aspect ratio before shooting to ensure proper framing
- Consider creating multiple versions of content for different platforms (horizontal for YouTube, vertical for TikTok)
- When scaling images, always lock the aspect ratio to prevent distortion